How generous: Skype wants to give us unlimited calling for free for an entire month. That means you can call landlines in over 40 countries and mobile phones in several countries without paying a dime. There are two catches, though: You have to claim your free month today (Nov. 15) and the offer is only available for existing Skype users.

By existing Skype user, it means you have been registered with Skype for more than 29 days. While there's no obligation to continue using the Unlimited World subscription, you do have to enter valid payment details—so either put in a one-time credit card number or mark your calendar for 30 days from now so you remember to cancel in time (if you wish to).

The free unlimited calling is worth $13.99. If you have friends or relatives in far-off places, head over to Skype before the day is over.